Study On Synthesis,Modification And Photocatalytic Properties Of Graphene Carbon Nitride Photocatalysts

With the rapid development of society and economy,the excessive exploitation of non-renewable hydrocarbon fossil fuels and the massive discharge of industrial waste water,human society is facing a serious energy crisis and environmental water pollution.It is well known that photocatalytic water cracking to convert solar energy into clean hydrogen energy is considered an attractive and promising strategy,In addition,the photocatalytic oxidation process can oxidize most of the organic pollutants so as to remove the organic matter in the organic wastewater,and finally realize the purpose of energy saving and removal.Therefore,the use of this photocatalytic technology and combination of photocatalysis oxidation and photocatalysis reduction process,this project can build a stable and efficient photocatalytic system degradation of organic pollutants of water aquaculture and synchronization of photocatalytic decomposition of hydrogen,sewage disposal and synchronization for renewable new energy,hydrogen is to solve environmental pollution problems of globalization also relieve the energy crisis.In this paper,a new type of graphene-like carbon nitride material?g-C₃N₄?and a composite material of graphene-like carbon nitride material modified by metal and aromatic hydrocarbons was prepared to explore the performance and application of this composite semiconductor catalyst in the simultaneous realization of photocatalytic hydrogen generation and pollutant removal.The C-GCN?brown?and Y-GCN?yellow?materials were first synthesized by high-temperature calcination with urea produced in 12 years and urea produced in 16years?the same pharmaceutical production company?as the precursor under the same environmental conditions,and through a lot of characterization methods of C-GCN material structure are found imide group outside of triazine ring.By optoelectronic chemical testing and catalytic hydrogen production experiments,the results show that after Pt deposition,the photocatalytic hydrogenation rate of the C-GCN material was0.688 mmol h^-1g^-1,respectively,which was about 5 times higher than that of the Y-GCN material(0.124 mmol h^-1g^-1).Its efficient catalytic effect is mainly due to the C-GCN materials with better visible light absorption and the higher separation efficiency of photogenerated electrons and holes and imide group of coupling and coupling effect of Pt.In order to solve the problem of g-C₃N₄ high recombination rate of photolithogenic carriers,we use doping transition mental Fe element and transplantation of terephthalaldehyde modified g-C₃N₄ to synthesize Fe-g-C₃N₄ and CNTE material,and then by building with heterogeneous image into get FeCN/CNTE heterojunction material.We study systematacially the experimental effect and mechanism over photocatalytic hydrogen production and synchronous to remove organic pollutants 4-NP solution.According to the experimental results,the 30%FeCN/CNTE material composed 30%?wt%?Fe-g-C₃N₄ supported on the surface of CNTE showed the best photocatalytic hydrolysis rate and degradation efficiency of 4-NP,respectively the removal rate of 4-NP as 93%,and the H₂ yield after 2h was0.86mmol^-1g^-1?the amount of catalyst used was 20mg?.At the same time,we also elaborate the mineralization process and mechanism of degradation of 4-NP and study the synergistic and inhibitory relationship between pollutant degradation and photocatalytic hydrogen production rate.